Power conditioners

@tcatman 

Panamax and Furman are now owned by the same parent company.  As such, some of the Panamax and Furman units offer Series Mode protection.  While There are MOV’s in them, they are not MOV centric.  That is, the MOV is there to cover a rare edge case.  

My suggestion is, as always, use a whole-house surge protector in your electrical panel.  These are almost always MOV based, but are in the perfect place for MOV’s and usually have some device to tell you when they have been used up. 

Then use Furman with SMP (or whatever equivalent series mode protection you want) near your audio gear.  Related to your next question, because SMP is essentially a low-pass filter, they tend to work much better than a lot of EMI/RFI filters.  They start filtering noise around 3 kHz, which is actually super low compared to a lot of EMI/RFI filters which claim to start filtering around 50k-100kHz.  That is, SMP filters AC noise all the way down to the audio spectrum.  

When shopping for a Furman, make sure it says "SMP" to ensure you buy one with the series protection features.  They make many models which do not have series mode protection.  

“Everything we hear can be measured” is an unsupported belief.

@kennyc + 1

@larsman It is true there is no one measurement that correlates to what we hear.  The THD Wars back in the 1970's didn't help anything either.  But the fact is, the vast majority of ugly distortion mechanisms can be measured, if the engineer is creative and has the right equipment. 

The lower frequency for the cutoff requires larger and more expensive components.  This is why some companies chose a higher cutoff to have a less expensive product. In this case it's up to the PSRR rating of the downstream electronics to keep the noise out.  Not the best approach, but it's less money to buy.

A 3 to 6 KHz cutoff is an ideal Fc for AC Main filters, at least in my opinion anyway.